/**
 * Gets an array of the authorised user groups
 *
 * @return  array
 *
 * @since   1.7.0
 */
public function getAuthorisedGroups()
{
    if ($this->_authGroups === null) {
        $this->_authGroups = array();
    }
    if (empty($this->_authGroups)) {
        $this->_authGroups = Access::getGroupsByUser($this->id);
    }
    return $this->_authGroups;
}